[sc34wg3] SAM-issue term-scope-def

Marc de Graauw sc34wg3@isotopicmaps.org
Sun, 30 Jun 2002 17:05:32 +0200


[Jan Algermissen]

> No, as I said, I do NOT agree with that. If the extend of validity of a
> basename characteristic assignment is the scope {Dutch} then (at least I)
> draw the conclusion that it is NOT valid outside that scope. As you say,
> 'We are open only on Monday' implies that 'we are closed on Tuesday'.
>
> My point was, that 'economie' is NOT a valid basename for the topic
> if NOT *{Dutch}* applies, but that this says nothing about the validity
> of the potential validity of 'economie' as a mere name.
>
Jan,

I'll try to get it right this time.

You say, if I understand you correctly, that in the case described
'economie' is not a valid basename when {Dutch} does not apply, but that it
can be valid as a mere name. That raises the question what a 'mere name' is.
Not a variant, since 'economie' has in the example not been declared as a
variant. Do you mean an conformant application might for instance show
'economie' as a name to a user when {Dutch} does not apply, as long as that
application does not treat 'economie' as a basename? So that in a sense
<baseName> elements have a double use: as real basenames, which are unique
identifiers, and as name-strings, which can be used in whichever way an
application chooses? That makes sense, but it would imply that one can
restrict the extent of validity of the name 'economie' as a basename but not
as a name-string (mere name). I.e. the scoping of a <baseName> element would
affect only its use as a basename, not it's use as a name-string. I find
this couterintuitive and I do not think the standards (XTM, 13250) describe
it this way.

If this is what you mean, what do you think of this problem? If this is not
what you mean, then what is a 'mere name'?

BTW, it is appealing to say what you say (and what SAM suggests now) - when
a basename is scoped, it is *not* valid outside this scope. It adds a lot of
simplicity to the model. We might get around the counterintuitive
consequences by saying: when scoped, a basename is not a valid name *for
this topic* outside this scope. It might be a valid name *for the subject*,
that we do not know, and the Topic Map does not say anything about this. To
get back to our example:

[economy = "economie" / dutch]

This says that when {Cherokee}applies but {Dutch} does not, 'economie' is
not a valid basename for topic economy. It is however possible that
'economie' is a valid name for the subject that topic economy represents
when {Cherokee}applies but {Dutch} does not.

This seems like an intuitive way to define things and keep simplicity. It
would say, however, that 'economie' is not valid as a 'mere name' either for
*topic* economy when {Dutch} does not apply, just that it might be valid as
a 'mere name' for the *subject*.

This brings to light some interesting differences between our standards:
ISO13250: topic name = A string of characters specified as a name of a
*topic*
SAM: A base name is a name or label for a *subject*
XTM: A *topic* may have zero or more names

[Lars Marius Garshol]
> How about phrasing the definition of scope as shown below?
>
>   All topic characteristic assignments have a <term>scope</term>,
>   which defines the extent to which the statement represented by the
>   assignment is valid. Outside the context represented by the scope
>   the statement is not known to be valid. Formally, a scope is
>   composed of a set of subjects that together define the context. That
>   is, the topic characteristic is known to be valid only in contexts
>                                ^^^^^^^^^^^^^^
>   where <emph>all</emph> the subjects in the scope apply.

This means the existing definition would remain as it is (say *not valid*
instead of *not known to be valid*), though we could add a sentence
explaining these issues, i.e.: "This restriction does not say anything about
the relation between the subject and the characteristic in contexts where
where not all the subjects in the scope apply. It only restricts the
relation between the topic and the characteristic."

And we could say:

A base name is a name or label for a topic, and, indirectly, for the subject
the topic represents.

What do you think?

Marc